Major League Baseball continued to expand the toughest drug program in the major sports Thursday with the announcement that it will test for human growth hormone throughout the regular season and increase efforts to detect abnormal levels of testosterone.

Players were subject to blood testing for HGH during spring training last year, and the new agreement between management and the players' association expands that throughout the season. Those tests are in addition to urine tests for other performance-enhancing drugs.

Under the changes to baseball's drug agreement, the World Anti-Doping Agency laboratory in Laval, Quebec, will keep records of each player, including his baseline ratio of testosterone to epitestosterone, and will conduct Carbon Isotope Ratio Mass Spectrometry (IRMS) tests of any urine specimens that "vary materially."

"This is a proud and a great day for baseball," Commissioner Bud Selig said after two days of owners' meetings in Paradise Valley, Ariz. "We'll continue to be a leader in this field and do what we have to do."

The announcement came one day after steroid-tainted stars Barry Bonds, Roger Clemens and Sammy Sosa failed to come close to gaining election to the Hall of Fame in their first year of eligibility.

Commenting on the timing, Selig noted the drug program changes had long been in the works "but it wasn't too bad, was it?"

Selig reflected on how far baseball had come on performance enhancing drug issues.

"This is remarkable when you think of where we were 10, 12, 15 years ago and where we are today," he said. "Nobody could have dreamed it."

There were concerns within MLB that synthetic testosterone had become the new PED of choice among players. Last season, San Francisco's Melky Cabrera, then the NL's batting leader, Oakland's Bartolo Colon and San Diego's Yasmani Grandal drew suspensions for elevated testosterone levels. Milwaukee's Ryan Braun tested positive for elevated testosterone in October 2011 but had that result overturned on appeal due to collection irregularities, leading to a tightening of the rules of that system.

Baseball began random drug testing in 2003, testing with penalties the following year and suspensions for first offenders in 2005. Initial penalties were lengthened from 10 days to 50 games in 2006, when illegal amphetamines were banned. The number of tests has gradually increased over the past decade.

Selig called the latest change a "yet another indication how far this sport has come."

"Players want a program that is tough, scientifically accurate, backed by the latest proven scientific methods, and fair," union head Michael Weiner said in a statement. "I believe these changes firmly support the players' desires while protecting their legal rights."

Selig praised the cooperation of the players association, once a staunch opponent of drug testing.

Christiane Ayotte, director of the Canadian laboratory, said that the addition of random blood testing and a "longitudinal profiling program makes baseball's program second to none in detecting and deterring the use of synthetic HGH and testosterone."

She said the program compares favorably with any program conducted by WADA.

HGH testing remains a contentious issue in the National Football League. At a hearing last month, U.S. Rep. Elijah Cummings, the ranking Democrat on the House Oversight and Government Reform Committee, accused the NFL players union of trying to back out of HGH testing.

NFLPA spokesman George Atallah said at the time that the union is not backing out of anything but was looking to resolve scientific issues surrounding the tests. HGH testing is part of the 10-year labor agreement reached in 2011, but protocols must be agreed to by both sides.

Tom Haudricourt of the Journal Sentinel staff contributed to this report.